Adjustable suture strabismus surgery Overview Part 1 Christolyn

Adjustable suture strabismus surgery - Overview Part 1 - Christolyn Raj Adjustable suture strabisumus surgery

Overview Part 1 n Adjustable sutures n Indications n Patient selection n Anaesthetic considerations n Techniques n Complications Adjustable suture strabisumus surgery

Adjustable sutures in strabsmus surgery • Principle : to secure EOM to sclera with a sliding knot , then when pt is awake , the length of suture b/w attachment site and muscle may be shortened or lengthened Ø First described by Claude Worth , first practised by Jampolsky 1975 Ø No prospective RCTs to date on selective advantage of adjustable sutures Ø Few reports on use of adjustable sutures on children q Adjustable sutures in strabismus surgery. Hunter, D. Dingeman RS et al. J Paed Opthal 2009. Ø Number of surgeons decribe adjustable sutures in adults to improve immediate post-op alignment [refs 3, 17, 22, 26, 30 -32] Ø Summary by Hunter, Dinegeman et al. , promote use of adjustable sutures on ALL adults , including those with comitant strabismus & no prior surgery Ø Authors also describe use in children who met select criteria Adjustable suture strabisumus surgery

Standard indications for adjustable suture strabismus surgery Restrictive strabismus eg: TED Previous trauma or surgery Slipped, lost, disinserted muscles Incomitant deviations eg : Duane’s syndrome , MG • Any longstanding, complex strabismus • • Adjustable suture strabisumus surgery

Patient selection q Adjustable sutures can be used with recessed or resected muscles and also been successfully described on superior oblique tendon. Goldenberg-Cohen N, et al. 2005. Strabismus 13; 5 -10. • • • Most surgeons advocate adjustable suture technique in children aged 12 yrs & older and only younger if co-operative & may require two stages of anesthesia Active participation of parents is a key factor (Dawson et al. 2001) Can perfom “Q-tip” test to identify suitable pts – consists of touching a cotton tip to the MR or LR aspect of the unanesthetized bulbar conjunctiva as a pre- test tolerability Ø If patient fails Q-tip test : consider non-adjustable suture surgery or arrange for back-up sedation Adjustable suture strabisumus surgery

Anaesthetic considerations 1). Recovery of extraocular muscle function -GA: EOM function recovers when pt awakes -LA: short acting agents require 5 hrs minimum for motility to recover 2). Patient comfort & alertness in recovery -pre-medication: for post-op nausea -induction with propofol preferable , shorter acting muscle relaxants preferable -avoid opiate analgesia which may cause sedation & nausea -topical tetracaine is often sufficient -ketorolac early intraop is another option /7 is m. effective Adjustable suture strabisumus surgery

Anaesthetic considerations 3). Post-op nausea & vomiting -ondansetron is very effective & has few SE’s -use with dexamethasone may augment effects of ondansetron 4). Sedation protocol for suture adjustment -mainly for unco-operative pts -inform anaethetist -should be monitored in recovery room setting to ensure airway & basic monitoring equipment is readily available -may need propofol induction dose Adjustable suture strabisumus surgery

Surgical techniques Limbal vs fornix approach o Limbal appoach provides broad exposure but requires conjunctival closure post suture adjustment o Fornix approach may be more comfortable as sutures are covered Technique Bow tie o Sutures ae tied together in a single-loop bow-tie like a shoelace o At adjustment the bow is untied , muscle adjusted & re-tied, bow cut & converted to a square knot Sliding-noose o sutures are passed through scleral tunnels emerging <1 mm apart , a noose is created by tying a separate piece of suture around the scleral sutures Adjustable suture strabisumus surgery

Adjustable suture strabisumus surgery

Surgical techniques Semi-adjustable sutures o Described by (Kushner et al. ) to reduce muscle slippage whilst preserving potential for adjustment o Involves suturing corners of muscle to sclera & placing centre of muscle on adjustable Authors’ preferred technique o Describes “noose” suture o For adjustable recession standard hangback doses used o For adjustable resection an extra 1 -3 mm muscle is resected , then muscle allowed to hang back by same amt o After the sutures are passed , they are pulled to original insertion these sutures are secured to each other with an overhand knot- these joined sutures are ‘ple sutures’ o For the adjustable noose , an absorbable suture is used , placed underneath the pole sutures & wrapped around a second time, finally tying a square knot to prevent slippage o At adjustment the bow is untied , muscle adjusted & re-tied, bow cut & converted to a square knot Adjustable suture strabisumus surgery

Adjustable suture strabisumus surgery

Adjustable suture strabisumus surgery

Complications *Intra-adjustment complications : § Nausea& vomiting § oculucardiac reflex § possible bradycardia § Syncope *Postoperative healing process may be very inflammatory : § conjunctival suture granulomas etc § Adhesions Adjustable suture strabisumus surgery

Conclusion • Adjustable sutures provide a second chance to improve outcomes of initial strabismus surgery • However…. ü They can add to complexity of case ü Require appropriate patient selection ü Evidence to validate their advantage over convential surgery is still not universally acknowledged ü Difficult learning curve involved Adjustable suture strabisumus surgery